"I can so confirm," Jackson Jr.'s attorney, Brian Heberlig, said when asked about the guilty plea. The guilty plea is for the one count of wire fraud, mail fraud and making false statements listed in the court document. Jackson could be sentenced to up to five years in prison.

Jackson resigned last year after winning reelection in November. Last summer, he was hospitalized for what was later said to be bipolar disorder.

Jackson's wife is charged with filing false tax returns.

The guilty pleas cap the downfall of a onetime Democratic rising star who had been talked about as a possible Illinois senatorial or presidential candidate.